1. Field of the Invention
The present invention relates generally to an electric powered vehicle using a compact motor and transmission configuration, and more particularly to a compact motor and transmission axially mounted within a wheel hub.
2. Brief Description of Related Art
Conventionally, electric driving units that drive a wheel with an electric motor, as disclosed, for example, JP-A-H11-34965 disclosed electric motors where the motor output shaft is parallel to the wheel axle. The electric driving unit shown in JP-A-H11-34965 is used as a driving source for an electric two-wheeled vehicle and provided with a swing arm for supporting a rear wheel.
The swing arm for supporting the rear wheel has an electric motor, a transmission and an axle that are provided at its oscillating end and also has a control unit for controlling the electric motor that is mounted to the arm section of the swing arm. The electric motor and the transmission are installed such that their shaft axes are parallel to the transverse direction of the vehicle body, the transmission is arranged in front of the axle in the longitudinal direction of the vehicle body, and the electric motor is located above the transmission.
The control is housed in a storage compartment isolated from the electric motor and is electrically connected to the electric motor through wires.
In the conventional electric driving unit described above, one compartment for housing an electric motor and another compartment for housing a control unit are formed separately. To form the separate compartments, larger volumes of partition walls are required, causing the unit to be larger as a whole increasing the production costs. The arrangement in which the transmission and the electric motor are and the transmission and the axle are placed in front of each other also to be larger.
Additionally, long conductive wires for connecting the control unit and the electric motor are required, because the former is located remotely forward from the latter. The expense for manufacturing long conductive wiring needed to allow the control unit to communicate with a remote electric motor increases production costs.
Furthermore, since the conductive wires between the motor compartment and the control unit compartment are exposed externally, those exposed wires may be damaged from pebbles thrown up by the rear wheel during operation. The increase in the number of electrical connections increases the possibility of damage to the electrical connections and the reliability thereof will be reduced.